1. Field of the Invention
This invention relates to communications monitoring and "logging" equipment; and more particularly relates to recording equipment used for recording all communications received or sent over a number of communications channels over substantial periods of time.
Communications loggers typically are used to make continuous or nearly continuous recordings of all telephone or radio communications to and from a single location, such as a police station or fire station. Typically, loggers are multi-channel magnetic tape recorders which record communications on each of a substantial number of telephone lines in closely spaced parallel tracks on a magnetic tape.
Because of the critical importance in many applications of communications recorders, such systems must meet many special requirements. Thus, such system should provide the capability to provide back-up monitoring of critical channels. Further, because of the highly variable nature of particular applications; which may involve from a few to hundreds of communications channels to be monitored, and where the importance of back-up protection may vary, both from application to application and from channel to channel, it is highly desirable that communications recorders be of a modular form readily adaptable to different applications. It is also highly desirable that such various configurations of communications recording systems include a system of user interaction which is readily adapatable to various configurations, and which enables a user to easily determine status and other information relating to particular channels.
Also because of the critical nature of the information recorded in many applications, security of communications recording systems is critical. Two aspects of this security are identification of the particular system which generated a particular tape and physical security of tapes being recorded.
In prior systems it was known to identify particular tapes by recording a unique identification code on a tape as it was being recorded, typically by modulating the guard tone on a selected channel. However, from time to time, problems arose when it became desirable to change this identification number, for example, when a system was physically relocated, since the identification number was hardwired or otherwise unalterably recorded in the system.
Security of tapes was provided in prior systems by generally limiting access to the system to trusted personnel. Limiting access in this manner, however, created problems for low level tasks such as changing full tapes when needed.
2. Objects of the Invention
Thus, it is an object of the subject invention to provide a system for monitoring signals received on at least one communication channel having improved back-up capability.
It is another object of the subject invention to provide failsafe back-up capability in such a system.
It is still another object of the subject invention to provide back-up capability in a system for monitoring communications which includes a system control unit where back-up capability is provided even in the event of failure of the system control unit.